Terpene containing polymers and process therefor



United States Patent 3,510,461 TERPENE CONTAINING POLYMERS AND PROCESSTHEREFOR Bernard J. Davis, Bil-oxi, Miss., assignor to ReichholtlChemicals, Inc., White Plains, N.Y. No Drawing. Filed May 29, 1968, Ser.No. 732,866 Int. Cl. C08f 15/40 US. Cl. 260-80.78 7 Claims -ABSTRACT OFTHE DISCLOSURE Thermoplastic resins are formed by copolymerization of CH terpenes, either in pure form or in mixtures, with alkylidenenorbornene in presence of a Friedel-Crafts catalyst at temperaturesranging from about 0-100 C.

of solubility, thermoplasticity and compatibility with a 2 broad varietyof other substances. The polyterpene resins are available in a broadrange of softening points. Because of these characteristics and others,the polyterpene resins are ideally suited for a number of uses, as iswell known.

The commercially available solid, thermoplastic polyterpenes are terpenehomo and copolymers and are composed essentially of polymerized bicyclicand monocylic terpenes, predominantly beta-pinene. Other terpenes theseresins may contain are for example alpha-pinene, dipentene (dl,limonene), d-limonene, terpinenes, camphene, delta carene, betaphellandrene and the like and mixtures thereof. The predominantmonomeric terpenes employed are preferably alpha and beta pinene, anddipentene. Beta-pinene is by far the most efficient monomer in terms ofyield and softening points obtainable, but unfortunately, beta pinene isnot correspondingly the predominant terpene in turpentines, which arethe most commonly available source of terpenes for the production ofterpene resins. Gum turpentine, obtained from live trees is richest inbeta-pinene, but increasing demand for pine lumber and increasing costsinvolved in bleeding the trees, as well as earlier cutting, seriouslyrestrict the availability of gum turpentine, previously readilyavailable and richest in beta pinene.

This means that other methods must be found to supplant diminishing betapinene supplies order to Produce the desirable high melt points andyields this monomer affords. Typical compositions of commerciallyavailable turpentines are set forth in Table I.

TABLE I Refined Steam sulfate wood, distilled Gum, percent percent wood,percent Alpha pinene 63 66 75 Beta pinene 33 20 Trace Dipentene 2 5Other terpenes 2 10 point, while alpha pinene under the same conditionsyields 35% resin with an 84 C. softening point. Literature and the artshow that mixtures of the two monomers do not yield the final melt pointand yield expected based on the beta pinene content. This evidences thefact that alpha pinene in particular has a limiting effect upon thepolymerizability of beta pinene resulting in higher than usual yields oflow molecular weight oily polymers that must be stripped from the finalresin.

In view of the foregoing and the ever decreasing supply of pure betapinene, there is an increasing requirement for a terpene polymerizationsystem which would enable the resin formulator to produce high meltpoint resins in suitable yield from normally low yield producingmonomeric terpenes.

Accordingly, among the objects of this invention are thermoplasticresins formed by the copolymerization of C H terpenes, either in pureform or as mixtures, with an alkylidene norbornene such as ethylidenenorbornene or methylidene norbornene. Also included within thisinvention is a process of preparing resins in relatively high yields andin a variety of softening points composed of copolymers of terpenes andan alkylidene norbornene, particularly high yields of various softeningpoints wherein the terpene is predominantly alpha pinene or othernormally difiicultly polymerizable terpene.

Preferably the amount of C H terpene used is at least 50% by weight ofthe combined weight of said terpene and the alkylidene norbornenes.

The alkylidene norbornenes employed in this invention are commerciallyproduced by reacting butadiene with cyclopentadiene in one case toproduce ethylidene norbornene,

CH2 6 GH=CH C C 2 C I CH2 CH2 I] OH CHsH2C=C CH CH=CH CH2 OH orsimilarly propadiene or methyl acetylene with cyclopentadiene to givemethylidene norbornene. Both alkylidene norbornenes behave well in thepractice of this invention, but ethylidene norbornene is preferredbecause of lower cost.

Since ethylidene norbornene is preferred for the reason stated, laterreferences to it in this application are denoted by the descriptiveinitials (EN).

The ethylidene norbornene-terpene copolymer resins of this invention arethermoplastic and exhibit a softening point higher than that obtainablefrom the terpene involved under the same conditions.

The softening points of the resins obtained are directly related to theproportion of ethylidene norbornene employed with the terpene. There isan apparent maximum proportion of ethylidene norbornene that can beemployed with each individual terpene to afford resins soluble inaliphatic solvents. In fact, gel-like insoluble polymers will form whenthis proportion is exceeded even if the reaction is run in an aromaticsolvent like xylene. This threshold value is characteristic of eachmonomeric pure terpene and is inversely proportional to their normalreactivity when classed by normal yield and melt point. In other wordsbeta pinene will tolerate much less modification with ethylidenenorbornene to provide a soluble resin than will alpha pinene. Thisthreshold can easily be detected on filtration of the neutralizedreaction mixture. In those cases where the value has been exceeded,filtration is slow to impossible because of gel formation.

The maximum threshold limits for the following pure terpenes have beendetermined during the course of a 3 large number of experimentalpolymerizations. They are as follows:

Pure monomer: Bicyclononadiene, mole 1 mole beta pinene A 1 mole d,llimonene A 1 mole 3, limonene /3 1 mole beta phellandrene A 1 mole alphapinene /2 It was found that the threshold value remains the same for themost reactive monomer in a .given mixture. An amount acceptable to aless reactive monomer in a mixture results in gelation since thequantity of ethylidene norbornene employed was in excess of the limitfor the more reactive monomer present. In other words, a 50/50 mixtureof beta-pinene and alpha-pinene can only tolerate /8 mole ethylidenenorbornene based on the beta pinene present and not the mole that mightbe expected.

The resins of this invention include copolymers of terpenes andethylidene norbornene which are polyterpene-like in character, primarilywith respect to the solubility, compatibility and thermoplasticitycharacteristics of the presently commercially available polyterpenes.

As a general procedure the ethylidene norbornene and the terpene arepremixed in the desired ratio. They are added slowly to a cooledreaction medium consisting of a suitable solvent and the catalyst atsuch a rate so as 4 of from about 25 C. to about C. or from about 30 C.to about C. provide highest yields with minimum color.

The reaction time covering the time of addition of monomer or catalystrequires one hour. The reaction mass is then held for 1% hours at roomtemperature. The product can then be quenched in water with subsequentseparations and washings to remove the catalyst or as we prefer, treatthe reaction mixture with lime and attapulgus clay (supplied by Minerals& Chemicals Phillip Corp., Menlo Park, NJ.) employing 2 /2 times theamount of catalyst of each of these materials. After addition of theclay and lime, the mixture is heated to C., filtered and then inert gassparged to 220 C., steam sparged to 235 C. and held at this temperatureuntil the ratio of condensed water to oil coming over is 9.8 to 0.2. Thefinal resin is then poured.

In order that those skilled in the art may better understand thisinvention, the following examples are given which are illustrative ofthe preparation of the invention but are not intended for purposes oflimitation.

EXAMPLES The resins produced and the conditions of the reactions aresummarized in Table II. In those cases where addi tion is denoted asdirect, the catalyst was added to the monomer-diluent; where denotedindirect the monomer was added to the diluent-catalyst.

TABLE 11 [Direct addition] Moles in reaction Reaction Reaction HoldSoftening ime, temp. time, Yield, point Example Terpene Terpene ENSolvent; Catalyst hrs. 0. hours percent C.

1 Beta pinene 1 Xylene-. A101 1 25-30 1% 103 155 2.... .-d0 1 HeptaneAlCl; 1 25-30 1% 150 3 .do 1 Xylene-.. A1013 1 30-35 1% 152 4---. Alphapinene 1 ..do A10 1 30-35 1% 75 135 5- do 1 1 30-35 1% 65 6-. do 1 130-35 1% 55 105 7.. Dipentene- 1 1 30-35 1% 70 8-. B-phellandrene- 1 130-35 1% 90 9.. d-Limonene 1 1 30-35 1% 80 130 10 Alpha pinene. i? 130-35 1% 90 Beta pinene g 11 d0 1 1 30-35 1% 95 120 Alpha pinene 1 130-35 1% 70 110 Gum turpentine 1 1 30-35 1% 75 140 Refined sulfate Wood1 1 30-35 1% 80 138 turpentine. 15 Steam dist. wood turpentine... 1 130-35 1% 77 138 [Indirect addition] Moles in reaction Reaction ReactionHold time, temp., time, Yield, Soft. pt., Example Terpene Terpene ENSolvent hrs 0. hours percent C.

16 Beta pinene 1 1 25-30 1% 100 17.-. Alpha pinene 1 1 25-30 1% 72 13118- "do 1 1 25-30 1% 61 116 19 -do 1 1 25-30 1% 53 102 20.-. Dipenten 11 25-30 1% 68 121 to maintain the desired temperature of reaction. Thesolvent can be aliphatic, aromatic or mixtures thereof, or a chlorinatedhydrocarbon. The catalyst can be aluminum chloride, aluminum bromide, orany acid reacting metal halide suitable as a Friedel Crafts catalyst orphosphorous pentafluoride or boron trifluoride or any suitable complexesof these two gases. For practice of this invention aluminum chloride ispreferred. It can be employed at a rate of ll0% based on the weight ofthe reactive monomers.

Higher melt points can be obtained by slowly and carefully adding thecatalyst to all of the monomer previously diluted with the reactionmedium solvent. For most cases a dilution of 35-50% monomer is easiestto control though the concentration of monomer may vary from 10-90%,given suitable cooling or handling facilities.

The reaction can be run at temperatures ranging from about 0 C. to about100 C. but the range from about 20 C. to about 65 C. is suitable and arange of from about 25 C. to about 45 C. is desirable, and ranges Whilethe examples shown demonstrate the optimum concentration of EN, there isno reason that lower concentrations of this monomer cannot be employed.In fact, higher concentrations can be employed if the gel is a desiredproduct for use in such solvent free systems as rubber milling when thegel can act as a tackifier but for most purposes, where the resinsolubility is a critical factor, the concentration of the EN should notexceed the previously explained threshold value.

It is obvious to those skilled in the art that other modifications andvariations of the present invention are possible in the light of aboveteachings. It is therefore to be understood that changes may be made inthe particular embodiments of the invention described which are withinthe full intended scope of the invention as defined by the appendedclaims.

What is claimed is:

1. A process of forming a thermoplastic soluble copolymer comprisingreacting an alkylidene norbornene with a C H terpene selected from atleast one member of the group consisting of monocyclic and bicyclic C Hterpenes in presence of a Friedel Crafts catalyst at temperaturesranging from about 0 C. to about 100 C.

2. The process according to claim 1 wherein the amount of C H terpeneused is at least 50% by Weight of the terpene and the alkylidenenorbornene.

3. A process according to claim 1, wherein the alkylidene norbornene isat least one member of the group consisting of ethylidene norbornene andmethylidene norbornene,

4. A process according to claim 1 wherein the C H terpene is at leastone member of the group consisting of beta pinene, alpha pinene,dipentene b-phellandrene, d-limonene, and turpentine.

5. A process according to claim 1 wherein the catalyst is aluminumchloride.

6. A process according to claim 1 wherein the temperature ranges fromabout 25 C. to about 35 C.

7. A thermoplastic soluble copolymer prepared accorda. ing to process ofclaim 1.

References Cited UNITED STATES PATENTS 3,151,173 9/1964 Nyce 260666 10JOSEPH L. SCHOFER, Primary Examiner R. S. BENJAMIN, Assistant ExaminerUS. Cl. X.R.

